Figurative sense of "anticipate, look forward to" developed in Latin and is attested in English from c.1600. Also from c.1600 as "regard as about to happen." Meaning "count upon (to do something), trust or rely on" is from 1630s. Used since 1817 as a euphemism for "be pregnant." In the sense "suppose, reckon, suspect," it is attested from 1640s but was regarded as a New England provincialism. Related: Expected; expecting.